Currently, a CDN (Content Delivery Network, content delivery network) network is generally used in the communications field to enable a user to acquire required content from a network.
As shown in FIG. 1, FIG. 1 is a CDN network architecture diagram. A Cache (cache) is placed in proximity to a user in a network, so that the user can acquire required content nearby, thereby effectively improving a speed of accessing resources. The CDN is properly combined with a mobile communications network, which can effectively speed up data distribution, especially video data distribution.
Currently, there are two positions at which a cache function can be implemented. One is that a cache is added in a radio access network node, generally in an eNB (evolved Node B, evolved NodeB), an RNC (Radio Network Controller, radio network controller), or a BSC (Base Station Controller, base station controller). The other is that a cache is added between a PDN (Packet Data Network, packet data network) and a P-GW (PND Gateway, packet data network gateway).
After a cache is added by using the foregoing two manners, a main manner of caching content is passive caching; that is, the Cache stores content accessed by a UE (User Equipment, user equipment), and when another UE accesses the same content, the content cached in the Cache is directly provided to the UE. Although a distance between a user and content is shortened by using this method, when acquiring required data, the user still needs to first establish a connection to a network, waits for transmission and buffering of initial video, and can play the video only after buffering time is long enough, which cannot meet an on-demand requirement of the user.